Siemens S7-300 is now spare-parts only. What that means for your line.

November 9, 2026 · 4 min read

The short version

• Siemens moved the SIMATIC S7-300 and ET 200M families into product phase-out in October 2023.
• Regular ordering ran for about two years. Since 1 October 2025 the products are in the spare-parts phase (Siemens lifecycle status PM410): no new projects or system extensions, replacement parts only.
• Siemens describes that spare-parts phase as lasting about eight years — roughly to 2033 — after which availability ends.
• The usual successors are the S7-1500 controller family with ET 200MP or ET 200SP I/O, engineered in TIA Portal.

What "spare parts only" means in practice

Your S7-300 does not stop working on a date. What changes is the risk around it:

• Lead time and price. Parts are now built and stocked as spares, not as catalogue products. Distributors already warn of longer lead times and higher prices.
• No expansion. Adding I/O or a new station to an S7-300 system now means sourcing spares, not ordering standard product.
• Shrinking know-how. Fewer people maintain STEP 7 Classic projects every year, and the hardware will keep ageing on your floor.

A practical plan (in this order)

1. Back up every program now — CPU, HMI and drives — and confirm you can open each project offline. A failed CPU with no backup turns a parts problem into a rewrite.
2. List what you have. CPU and module order numbers, firmware, quantities, and which machines stop the plant if they go down.
3. Hold critical spares for the machines in that last group while parts are still obtainable.
4. Decide per machine: keep running on spares, partial upgrade (CPU first, existing I/O kept for now), or full migration to S7-1500 with ET 200MP/ET 200SP.
5. Plan the cut-over around production. Test the converted program offline, prepare I/O checks, and keep the old CPU and program ready to put back for the first start-up.

Where migrations go wrong

• Converting the code but not re-checking timers, counters and analog scaling on the new platform.
• Changing the HMI at the same time without a tag-by-tag check.
• Leaving drawings and I/O lists at the old revision, so the next fault starts with wrong documents.

How AranVision helps

We back up and document existing Siemens systems, upgrade older TIA Portal and STEP 7 projects, and plan S7-300 to S7-1500 migrations machine by machine — with the program backed up before any change and documents that match what is installed at hand-over. Planning a migration or need spares advice? Call 437-228-4818 or send your system details through aranvision.ca/contact.